Traction-engine.



W. 0. STARK.

TRACTION ENGINE. APPLICATION FILED APR; 5, l9l6.

i WK mo W. 0. STARK.

TRACTION ENGINE.

APPLICATION FILED APR-5, 1916.

1,228,709. Patented June 5, 1917 4 SHEETS-SHEET 2.

INVENTOR: W 0. STERIC ATTORNEYS.

W. 0. STARK.

TRACTION ENGINE.

APPLICATION FILED APR. 5. ms.

Patented June 5, 1917 4 SHEETS-SHEET 3- INVEN TOR: IS'T/YRK,

Wa /a4 You ATTORNEYS.

W0. BY

4 SHEETS-SHEET 4- Patented June 5, 1917.

w. 0. STARK. TRACTION ENGINE.

APPLICATION FILED APR-$1916.

" ATTORNEYS.

TAT FATE FREQ WILLIAM O. STARK, OF CHICAGO, ILLINOIS, ASSIGNOR T0IBULLOCKTRACTOR CO., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

- TRACTION-ENGINE.

Continuation in part of application Serial To all whom it may concern:

Be it known that I, WILLIAM O. STARK, a citizen of the United States,and resident of Chicago, in the county of Cook and State of Illinois,have invented certain new and useful Improvements on Traction-Engines,for which I have made application for Letters Patent of the UnitedStates, filed August 20, 1913, Serial No. 785,675., and of which thispresent application is in part a continuation; and I do hereby declarethat the following description of my said invention, taken in connectionwith the accompanying sheets of drawings, forms a full, clear, and exactspecification, which will enable others skilled in the art to which mysaid invention appertains to make and use the same.

Ths invention has general reference to traction engines, and especiallythat type of tractors having endless tracks on which the machine isdesigned to travel; and it con sists, essentially, in the novel andpeculiar combination of parts and details of construction, ashereinafter first fully set forth and described, and then pointed out inthe claims.

In the drawings already mentioned, which serve to illustrate thisinvention more fully, and Whichform a part of this specification, Figure1 is a side elevation of a tractor em bodying my invention. Fig. 2 is aplan of the chassis of the machine. Fig. 3 is a sectional view on line33 of Fig. 2. Fig.4 is a similar view on line 4-4 of Fig. 2. Fig. 5 isapside elevation of one of the trucks detaclied; and Fig. 6 is a plan ofthe same.

Fig. 7 is a longitudinal sectional view of several articulated membersforming a part of the endless track, the figure being drawn on line 77of Fig. 8. Fig. 8 is a sectional plan of two adjacent members of saidendless track, on line 88 of Fig. 7. Fig. 9 is a side elevation of afragment of a track member; and Fig. 10 is a transverse section thereofon line 1010, of Fig. 8.

ike parts are designated by the same characters and symbols of referencein all the figures.

The object of this invention is the production of an eflicient,serviceable, and durable traction engine in which endless tracks areemployed for both, propelling and steering.

the machine.

In the drawings, A, deslgnates the chassis Specification of LettersPatent.

No. 785,675, filed August 20, 1913. This application filed April 5,1916. Serial No. 89,202.

or subframe of this machine. It includes longitudinal sills 12, 13,preferably formed of channel -bars, and I-beams 14, 15, fourlongitudinal beams 16, 17 18, 19, connecting the end I-beams 14, 15, twotransverse channels 20, 21, connected to the longitudinal I-beams 17,18, and two longitudinal channels 22, 23, located upon, and connectingthe channels 20, 21. In the rear of the transverse channel 21, there arelocated two-transverse I-beams 24, 25, also connected to the twolongitudinal I-beams .17, 18, and upon these beams there is placed anopen bed plate 26, upon which is mounted the friction drive, constructedsubstantially like the friction drive shown and described in aspecification, which I have prepared and filed August 20, 1913, SerialNo. 785,674, and to which reference may be had for a full disclosure ofthe said invention.

Upon the longitudinal channels 22, 23, there is mounted a motor B,preferably of the internal combustion type, the engine shaft of whichactuates the driving mechanism, as will hereinafter more fully appear.

Near the forward ends of the sills 12, 13, there are pendant plates 28,28 29, 29, the lower ends of which afford guides for truck frameshereinafter described, in conjunction with further pendant plates 30, 3031, 31*, at the rear end of the chassis A, all of said plates havingbraces 32, to afford stiifeners for said plates to prevent lateralmovement.

The propelling or traction mechanism proper, includes two endless trackbands C, mounted in truck frames occupying the spaces 33, 34, Fig. 2,formed by the longitudinal sills and I-beams 12, 16, 19, and 13, of thechassis, one of said truck frames and its appurtenants being shown indetail in Figs. 5, and 6, "and comprise two side bars 35, 35 in parallelspaced relation, said side bars having at their rear ends bearings 36,36 for the reception of a shaft 37, upon which shaft there is mounted atwo-part sprocket wheel 38, which constitutes the shaped link sectionsare hingedly connected by pins or bolts 75. From the side walls of thelink sections 73 project laterally, cylindrical bosses 76, which bossesform, as it were, racks which are engaged by the cogs or teeth 77,. ofthe twin driver sprocket 38, and thereby cause the forward, or rearwardmovement, as the case may be, of the machine. It will thus be seen thatinasmuch as the bosses 76 project from both sides of the box-shaped linksections 73, and are engaged'by the twin driving sprockets, the movementof the machine on its endless track is greatly facilitated.

The twin sprocket 38 is preferably formed in two parts each of which hasone of said sprockets, and one half of a drum 78, which drum runs on thetrack surface 74, of the link sections 73, and which drum carries itsportion of the superposed weight of the machine, said drum and thebearings or track-- surfaces 74 being made rather wide for obviousreasons, there being no weight or load whatever imposed upon thesprocket portion of said twin driving sprocket. And for the same reason,the bearing rollers 45, and supporting guiding rollers 48, are made withcorrespondingly wide faces.

The cogs or teeth 77 of the sprocket wheels are outwardly flared, asshown at 79, in Fig. 6, and terminate in nearly sharp edges, which inrotation of the sprockets, function as knives to cut away any solidmatter that may adhere to the link sections.

I have shown in the drawings, the driving twin sprocket wheel providedwith only four sprocket teeth each, but it is evident that any other,larger number, of sprocket teeth may be employed if desired or foundadvisable.

At their forward ends, the side bars of the trucks are slotted asindicated at 38 to receive bearings 39, 39 in which there is rotating ashaft 40, upon which there is mounted a two-part sprocket wheel 41,constituting the driven sprocket, said endless track band C, beingtrained over both, driver and driven "sprockets.

The shaft 37 passes through. bearings 42, 42*, Fig. 4, formed in therearwardly located plates 30, 30 (and 31, 31 respectively) so that thetruck frames are pivotally connected to the chassis at their rear ends,thereby permitting the forward ends of the same to rise and fall tofollow the undulations of theground over which the tractor is beingmoved.

Pending from the side bars 35, 35 there are a series of bearings 43, inwhich rotate shafts 44, on which are mounted the rollers 45, whichsustain the endless track band at its lower run; and from said side barsthere project, upwardly, similar bearings 46, in which rotate shafts 47,on which are mounted guide rollers 48, that sustain the upper run of thechain C, these, and several or all of the guide rollers being flanged toprevent the chain 0, from swinging sidewise.

At the forward ends of the side bars 35, 35 of the truck frame there arelocated screw bolts 49, one end of each being fastened to thecorresponding bearing 39; nuts 50, being located on said screw bolts,which when rotated in one direction, will draw the bearings 39 in onedirection, and when rotated in the opposite direction, allows thebearings 39 to move correspondingly. By means of this device I amenabled to take up any slack in the chains C that will occur in courseof time by wear of the moving parts.

In order to relieve the machine from the effects of jars and jolts whenmoving over rough roads, I provide, preferably elliptical, springs 51,fastened to the forward end of each side bar. These elliptical springsare connected at their extremities to one end of upstanding links 52,Fig. 1, the other ends of said links being pivoted, in pairs, to shafts71, having hearings in brackets or bosses 70, secured to the under sideof the longitudinal beams 12, 16, 19, 13, respectively. By thus flexiblysupporting the forward end of the main frame, I relieve the machine ofmost of the jars, jolts, and other severe usage to which this class ofmachines is especially subjected.

Referring to Fig. 1, there is mounted on the bed plate 26, an arcuatestandard 53, having bearings 54, for the reception of the engine shaft27; and between the uprights of this standard there are mounted onengine shaft 27, two, oppositely facing driver friction disks 55, 55These friction disks engage two friction driven disks 56, mounted onshaft 57 which carry, at their ends gear pinions 58, that mesh into spurwheels 59,

fastened to shafts 60, together with pinions 61, that engage spur wheels62, fastened to shaft 37, to rotate these shafts, and through them, movethe endless track band C, as already described.

In order to steer this machine by varying the speed of the endless trackbands, I employ mechanism which forms the subject matter of a separateapplication for Letters Patent, filed by me August 20, 1913, Serial No.785,674, and which include; hand wheel 63, which, when rotated, causes alateral movement of the driven friction disks, as fully described insaid application; while a handle bar 64, and associated mechanismaffords means for reversing the movement of the tractor.

I have hereinbefore described but one of the trucks, but have alreadystated the fact that there are two of these devices, one on each side ofthe machine; the one shown in Figs. 1 and 5 being the one located on theright side of the machine.

masses I shall now call attention to the fact that an imaginary linedrawn horizontally through the center of the shaft 37 forwardly, willshow that the center of the shaft 40 on which the forward sprocketwheels 4L1 are mounted, is located some distance above this horizontalline, or in other words, that the centers of these two shafts are not inhorizontal alinement, while the centers of the bearing rollers 45 are inhorizontal alinement.. It thus follows that at the forward part of thelower run of the endless track there are several links between the firstbearing roller 45, and the point where a link of the endless track beltengages the forward sprocket, which are upwardly inclined, therebyforming an incline in the track by which the ma chine isenabled toreadily mount obstructions, etc., in the road, while all of theremaining links of the ground run of the endless track between the firstbearing roller 45 and'a vertical central line through the rear sprocketshaft are normally in horizontal alinement, thereby combining with easeof mounting obstructions, a maximum traction efiiciency, which issuflicient tosustain this machine upon soft ground on which othertractors of the same weight, but having alesser area of tractor surfacewould be mired. This feature of my tractor is an important feature intraction enfgmes and contributes largely to its success tion.

I have hereinbefore disclosed the preferred mode of practising myinvention, but I reserve the right to make such and any changes as mightoccur to one skilled in the art to which this invention appertains, orto make any-and all such alterations as may be permitted under thedoctrine of equiv alents. V

Having thus fully described my invention I claim as new, and desire tosecure to myself by Letters Patent of the United States 1. In a tractorof the type described, an endless track band constructed of articulatedmembers, each member having two oppositely extending bosses, saidmembers being substantially box shaped, said members 111 operacomprisingtop and bottom members, said top members aflording a wide smoothuninterrupted track, and a driving sprocket,

said driving sprocket comprising a drum, said drum being constructed torun on said smooth upper surface, said drumhaving on its two marginsradially projecting teeth, said teeth being constructed to overlap thesides of said box-shaped members, to engage the oppositely extendingbosses'of said articulated members.

2. In a tractor of the type specified, an

endless track bandcomprising a series of shoes, each shoe having widebox-shaped member, the upper surface of said member being constructed toform a track, said boxshaped members being hingedly connected one to theother, there being a boss laterally projecting from opposite sides ofsaid boxeach of said members having lateral, axiallyalined projections,said projections extending from the sides of said box-shaped members,and a driving element for said endless band, said driving member being awide 7 drum constructed to roll on the said wide surface of said track,there being at the opposed margins of said drum radlally projectingteeth, said teeth being constructed to engage said projections at apoint medi-' 4 ally of the length of said teeth, there being no contactof said projections with sand teeth at the jointure of said teeth withsaid drum.

In testimony that I claim the foregoing as my invention, I have hereuntoset my hand.

